Electronic structure and optical properties of Nb-doped Sr2TiO4 by density function theory calculation

This paper investigates the effect of Nb doping on the electronicstructure and optical properties of Sr₂TiO₄ by thefirst-principles calculation of plane wave ultra-softpseudo-potential based on density functional theory (DFT). Thecalculated results reveal that due to the electron doping, the Fermilevel shifts into conduction bands(CBs) for Sr₂Nb_xTi_1-xO₄ with x=0.125 and the system shows n-type degeneratesemiconductor features. Sr₂TiO₄ exhibits opticalanisotropy in its main crystal axes, and the c-axis shows the mostsuitable crystal growth direction for obtaining a wide transparentregion. The optical transmittance is higher than 90% in thevisible range for Sr₂Nb_0.125Ti_0.875O₄.